Avalanche Flashcards
Avalanche
Is a mass of snow and ice that moves very rapidly down a mountainside
Describe an avalanche
A sudden event but rarely last more than a few minutes. However they are tremendously powerful moving at speeds up to 300kph
What can an avalanche sound like
Oncoming train
Where do most avalanches occur
Steep slopes between 35-45 degrees
How is an avalanche formed
Spring sunshine causes an increase in temperature
Melted layers, may freeze and form a layer of ice
Fresh snow falling on this layer can be unstable
Any disruption can cause upper layers of snow to lose grip and begin to slide causing an avalanche 
What are the effects of an avalanche?
Avalanche can obstruct anything in its path roads and railways can be blocked. Power supplies cut off and they can tear down trees and ski lifts. A powerful avalanche can destroy buildings. People can also be killed. 
90% of people
who die in avalanches triggered them themselves
Why do people usually die on an avalanche
Due to loss of oxygen when buried in snow rather than from getting too cold but they may also suffer impact injuries and fractures
To reduce the hazard of avalanches what do ski resorts do?
They monitor the state of the snow, the weather and then issue or warnings
What are some ways to prevent an avalanche?
Wooden fences to hold back snow on slopes
Avalanche sheds to protect railway lines
Wedges to protect electricity pylons
Walls on steep slopes to hold back snow
Mounds to slow avalanches on flatter ground
Plant trees to prevent avalanches from starting
What percentage of victims can survive
90% of avalanche victims can be recovered alive if they are dug out within the first 15 minutes
What should you do when faced with an avalanche?
Move above the break line
Moved to the side of the flow
Grab a sturdy tree or rock
‘ swim’ on top of the snow
If submerged cover your face
Make holes as snow slows
Raise hand above the snow
Breathe deeply before Snow hardens
